Some containers for food products, such as cookies and other snacks, typically include an outer wrapper. In one type of container, the wrapper surrounds a frame which acts as a tray to hold the food product and to protect the food product from damage. Other food products come packaged in plastic trays, such as thermoform trays, which are sealed on the top using some type of lidding material. One recent advancement in the art of food container closures includes a resealable closure disclosed in U.S. Pat. No. 6,918,532 (hereinafter “the '532 patent”), herein incorporated by reference, which discloses a wrapper which forms a top of the container, which top has an access opening covered by a resealable sealing panel.
In the packaging art, different structures have been used to indicate whether a package has been previously opened or whether the integrity of the package has been compromised, which structures are often referred to in the art as “tamper-evident” or “package integrity.” For example, one recent package integrity indicating closure is disclosed in U.S. patent application Ser. No. 11/500,497 (hereinafter “the '497 application”), herein incorporated by reference, shows a closure comprising a two-ply material having an inner film layer and an outer film layer forming a top of a container. The outer film layer has a sealing panel covering a portion of the inner film layer which, with the sealing panel, forms an opening. The package integrity feature comprises a panel of the inner film layer which separates from the sealing panel to indicate that the closure has been previously opened.
One recent advancement in the art of food containers having a package integrity feature is disclosed in U.S. patent application Ser. No. 11/693,751 (hereinafter “the '751 application”), herein incorporated by reference. The '751 application discloses a resealable closure having a package integrity indicator provided by a structure which breaks and/or produces an audible sound when the resealable closure is opened for a first time. The package integrity feature includes at least one strip initially affixed to two portions which comprise the resealable closure so that upon opening the resealable closure for a first time, at least one of the strips breaks, thereby indicating that the package has previously been opened. Package integrity is also provided by a movable panel or removable die-cut tab portions which are misaligned upon resealing of the closure, thus indicating that the package has previously been opened.
In the packaging art of non-food items, different methods have been used to indicate whether a package has previously been opened or whether the integrity of the package has been compromised, including the methods disclosed in U.S. Pat. Nos. 6,589,622; 6,767,604; and 4,679,693. U.S. Pat. No. 6,589,622 discloses a tamper-evident feature in the form of a label flap having a series of perforations which form a tamper indicating tab, such that when the label flap is initially removed from the package, the tamper indicating tab separates from the label flap along the perforations to indicate that the package has been opened. Similarly, in U.S. Pat. No. 6,767,604, package integrity is indicated by a label with pull tab having a pull tab perforation or other weakened portion which divides the tab into a pull portion and an end portion. U.S. Pat. No. 4,679,693 discloses a main pull tab adhesively sealed to a top surface of a package with an auxiliary pull tab which is completely removed from the main tab prior to opening the container.
There is a need in the art for a resealable container, preferably suitable for containing food items, which includes a new and improved package integrity indicator.